Have lost six large koi in past three months

[ctrgojo]

Glad to hear the cover worked!
I really liek teh way taro looks and I was thinking of getting some for the new pond build this spring but I think Im just going to play it safe with lillies and lotus...
How is the hospital tank??

 

[DrDave]

My hospital tank is basically an indoor resort for 3 of my 2 year olds this winter.

 

[Ellis Smith]

My hospital tank is a newly purchased 75 gallon aquarium. Previously used a bathtub in the house. The aquarium is much better but in this case turned out to be a mortuary. The fish had been sick since the 15th but my hospital tank was not set up until the 19th. I believe the koi died the following day but did not remove it from the tank until the 21st, when I was sure. To me, it does not appear emaciated as with the earlier koi death. Do you all agree? I do not feed my koi a lot, assuming there is adequate food in the pond. Removed a lot of mistletoe (photo below) in hopes that it was the culprit. My pond temperature is down to around 38 degrees F and all the koi are hiding under rocks in the deeper sections so I probably won’t know if any more are sick until the weather warms up. Here in Texas, that could be any time. Again, thanks for all the advice.
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[DrDave]

It could be they were too far gone and did not survive the tank getting established. It takes several weeks to get a tank bio system balanced with a few fish in it to get the process going.

They look like they were starving. When the water was warm were they eating?

 

[koikeepr]

That fish is totally ematiated. It is not properly proportioned in size anywhere. What is up with that net hanging in your pond and all the debris in it?? You need to lift the net up post haste. For one thing get a couple of pieces of PVC pipe at Home Depot and form a structure so that your net tents over it. All those leaves and twigs in the water pollute it and are certainly adding to your fish dying. Plus, the fish can become entangled in the net as well. Look at our winterizing posts for ideas on pvc frames.

You need to quickly do better for these fish. What are your water parameters? Do you do water changes during the normal season??

Something is totally off here. Fish don't just look like that and die for no reason. What are your water temps right now?

 

[Ellis Smith]

I am a bit slow to reply. The spirit of the forum locked me out for a week and until I could assure it that I was not involved in e-commerce. I am not sure who the spirit is but I can assure it that I have no connection to e-commerce.
In answer to some of the questions that were posted earlier:
The net over the pond was only there for a few hours while I cut away mistletoe from above. The photo was intended to give an idea of how much mistletoe had been above the pond. Half again as much was removed from the other side of my bridge the following day.
Water parameters are as follows:
Salt - .08%
CL - 0
Ph - 7.8
KH (carbonate hardness) - 235
GH (calcium & magnesium) – 180
Nitrite – 0
Nitrate – 0
Ammonia - 0
Temperature – 44 deg F

The high KH and Ph probably result from large amount of limestone used in pond construction. I have not changed the water since nitrate, nitrite and ammonia levels have been within tolerance. The Ph has slowly decreased from 8.4 to the present 7.8
over the three tears since pond construction.
I plan to raise the salinity (meter is new) to about .2% over the next few days. Is hardness a serious problem? I would rather not add a lot of city water to the pond but can direct a fairly large amount of rain water, when and if it rains, which could reduce the hardness.
I am not aware of any fish deaths since I removed the mistletoe but the weather has turned colder so most of the koi are staying under rocks and out of sight.

 

[DrDave]

Beware not to add rainwater off your rooftop. There are a lot of toxins in roofing materials and over time who knows what has come to rest on your roof that may also cause harm to your fish.

 

[nc0gnet0]

Are all the fish this thin? Looks to me like they are starving and severly underfed. This might further encourage them to eat things they may not normally eat, such as the berries etc that are falling into the pond. What do you feed and how often? I understand that it is cold now and you shouldn't feed, however they in no way have enough mass to support them through an extended cold spell.